PROJECT SUMMARY PRIMARY AIMS The long-term goal of this HeartMap Dynamic Registry is to ensure safety of automated external defibrillators (AEDs) by performing postmarket surveillance. AEDs are medical devices used to treat out-of-hospital cardiac arrest (OHCA). AEDs are distributed in locations anticipated to be close to the scene of cardiac arrest and are moved periodically from one location to another. There are 1.2 million pre-existing AEDs, and about 180,000 new devices installed annually. As increased numbers of AEDs have been installed in community settings, the Food and Drug Administration has received increased numbers of medical device reports. Importantly, there is no widely-deployed method of tracking their location and use in community settings. To plan for a national AED surveillance system, this pilot study will evaluate the feasibility of implementation and maintenance of a dynamic registry for surveillance of AED location and use. Our primary aim is to establish the feasibility of tracking AEDs by estimating attrition of registered AEDs. Attrition is defined as the proportion of AEDs that have unknown location or status six months after entry into the registry. SECONDARY AIMS Our secondary aims are to assess accrual and linkage. Accrual is defined as the proportion of AEDs that are tagged with a UDI and enrolled in the registry. Linkage is defined as the proportion of AEDs in the registry linked to: a social media database that describes pre-existing AEDs; a clinical electronic database that describes care for patients treated for OHCA; and an electronic medical record for hospitalized patients. METHODS Design Prospective cohort study of pre-existing and newly-installed AEDs in community settings. Setting This pilot study will be implemented in Seattle, WA and Philadelphia County, PA. Population Included AEDs will be those: a) Pre-existing in community settings and i. Identified by manufacturer or distributor; or ii. Identified by crowdsourcing techniques. b) Newly installed in community setting; i. Identified by owner during at time of installation. Included patients will be those treated for OHCA: a) Evaluated by organized EMS personnel and receive attempts at external defibrillation (by lay, police or EMS), or b) Receive chest compressions by organized EMS personnel, and c) Transported to a participating receiving hospital. Exposure of Interest Individual AEDs will be tagged with a Unique Device Identifier (UDI). This UDI consists of a label with a two-dimensional matrix code (QR code, Denso Wave Inc., Chita-gun, Japan). Then the UDI as well as the location and status of the device are recorded using open-source software native to contemporary smartphones and this information is passed to a database in real time via the internet (Provisional Patent # 61/498,424). The device-specific information in the database can be updated dynamically by rescanning the two-dimensional matrix code at each use of the AED. Analysis As this is a feasibility study to characterize accrual and attrition, there will be no formal interim analyses that would allow stopping the study for either efficacy or futility. The data will be monitored regularly by an independent DSMB to ensure study integrity and patient safety. The attrition rate will be summarized as a binomial proportion. Secondary measures will be summarized descriptively, as recommended for pilot studies. Sample Size We anticipate enrollment for three months will yield 2,000 AEDs with UDIs. If 90% of enrolled AEDs are known at six months, a 95% confidence interval will provide sufficient precision to reject an attrition rate below 0.886. If 80% of enrolled AEDs are known at six months, there will be sufficient precision to reject an attrition rate below 0.781.